Electrode of an electrowetting device

Abstract

An electrowetting display device including an electrowetting element with a first support plate, a second support plate, a first fluid and a second fluid immiscible with the first fluid. A voltage may be applied between a first electrode and a second electrode. At least one of the first electrode and the second electrode comprises a semiconducting material.

What is claimed is: 
     
       1. An electrowetting display device including an electrowetting element comprising:
 a first support plate and a second support plate; 
 a first fluid and a second fluid disposed between the first support plate and the second support plate, the first fluid being immiscible with the second fluid; 
 a first electrode located in the first support plate and a second electrode in electrical contact with the second fluid, for applying a voltage between the first electrode and the second fluid, 
 wherein at least one of the first electrode or the second electrode comprises a semiconducting material. 
 
     
     
       2. An electrowetting display device according to  claim 1 , wherein the semiconducting material is at least one: an intrinsic semiconducting material, a non-degenerate semiconducting material, a non-metallic semiconducting material, an organic polymer, or a material including at least one metalloid element. 
     
     
       3. An electrowetting display device according to  claim 1 , wherein the semiconducting material is at least one of: a semiconducting material including gallium, indium gallium zinc oxide, a polyfluorene polymer, poly(methyl methacrylate), or graphene. 
     
     
       4. An electrowetting display device according to  claim 1 , wherein the semiconducting material comprises at least one of: polycrystalline silicon, low-temperature polycrystalline silicon, or microcrystalline silicon. 
     
     
       5. An electrowetting display device according to  claim 1 , wherein the semiconducting material comprises polycrystalline silicon with a sheet resistance in the range of about 50 to 100,000 Ohm/square. 
     
     
       6. An electrowetting display device according to  claim 1 , wherein the first electrode comprises a layer of the semiconducting material having two substantially planar surfaces substantially parallel to each other, a thickness of the layer of the semiconducting material in a direction perpendicular to a plane of one of the substantially planar surfaces being in a range of one of: about 25 to 200 nanometers, about 25 to 150 nanometers, about 25 to 100 nanometers, about 25 to 75 nanometers, or about 25 to 50 nanometers. 
     
     
       7. An electrowetting display device according to  claim 1 , wherein the first support plate includes a transistor for controlling application of an electric potential to the first electrode, the transistor including a source terminal, a drain terminal electrically connected to the first electrode, a channel connecting the source terminal to the drain terminal, and a gate terminal separated from the channel by a dielectric material, a flow of electric current between the source terminal and the drain terminal, via the channel, being controllable by application of an electric potential to the gate terminal, wherein the channel comprises the semiconducting material. 
     
     
       8. An electrowetting display device according to  claim 7 , wherein the channel comprises a first layer of the semiconducting material and the first electrode comprises a second layer of the semiconducting material, each of the first layer and the second layer having two substantially planar surfaces substantially parallel to each other, a thickness of each of the first layer and the second layer being substantially the same in a direction perpendicular to a plane of one of the substantially planar surfaces. 
     
     
       9. An electrowetting display device according to  claim 8 , wherein the thickness of each of the first layer and the second layer is in the range of one of: about 25 to 200 nanometers, about 25 to 150 nanometers, about 25 to 100 nanometers, about 25 to 75 nanometers, or about 25 to 50 nanometers. 
     
     
       10. An electrowetting display device according to  claim 7 , the first electrode comprising the semiconducting material, wherein a deposition structure of the semiconducting material of the channel and of the first electrode is substantially the same. 
     
     
       11. An electrowetting display device according to  claim 7 , the first electrode comprising the semiconducting material, wherein the first electrode and the channel are formed using at least one of: chemical vapour deposition, plasma enhanced chemical vapour deposition, or physical vapour deposition. 
     
     
       12. An electrowetting display device according to  claim 7 , the first electrode comprising the semiconducting material, the first support plate including a layer comprising the dielectric material and having a surface on which the channel and the first electrode are positioned, wherein at least part of the layer comprising the dielectric material separates the gate terminal from the channel. 
     
     
       13. An electrowetting display device according to  claim 1 , the first support plate including a fluid adjoinment layer positioned on a surface of the first electrode and having a surface for adjoining the first fluid, the fluid adjoinment layer comprising a material with a greater wettability for the first fluid than for the second fluid upon application of a substantially zero voltage between the first and the second electrodes. 
     
     
       14. An electrowetting display device according to  claim 1 , the second support plate including a substrate with a surface on which the second electrode is positioned, the second electrode comprising the semiconducting material. 
     
     
       15. An electrowetting display device according to  claim 14 , the second electrode comprising a layer on the surface of the substrate. 
     
     
       16. A method of manufacturing an electrowetting element, the method comprising:
 depositing a semiconducting material on at least one of a first support plate surface or a second support plate surface; 
 forming at least one of a first electrode on the first support plate surface or a second electrode on the second support plate surface from the semiconducting material deposited respectively on the at least one of the first support plate surface or the second support plate surface; and 
 disposing a first fluid and a second fluid between a first support plate having the first support plate surface and a second support plate having the second support plate surface, the first fluid being immiscible with the second fluid. 
 
     
     
       17. A method according to  claim 16  comprising:
 forming the first electrode from the semiconducting material deposited on the first support plate surface; and 
 forming a channel from the semiconducting material deposited on the first support plate surface, for connecting a source terminal to a drain terminal of a transistor. 
 
     
     
       18. A method according to  claim 17 , the forming the first electrode and the forming the channel comprising at least one of: chemical vapour deposition, plasma enhanced chemical vapour deposition, or physical vapour deposition. 
     
     
       19. A method according to  claim 17 , comprising the forming the first electrode during the forming the channel, using the same deposition technique. 
     
     
       20. A first support plate for an electrowetting display device including an electrowetting element comprising:
 the first support plate and a second support plate; 
 a first fluid and a second fluid disposed between the first support plate and the second support plate, the first fluid being immiscible with the second fluid; 
 a first electrode located in the first support plate and a second electrode in electrical contact with the second fluid, for applying a voltage between the first electrode and the second fluid, 
 wherein the first support plate includes the first electrode which comprises a semiconducting material.